std::move
From Cppreference
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| Defined in header <utility>
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| template <class T>
typename std::remove_reference<T>::type&& move(T&& t); | (C++11 feature) | |
Obtains an rvalue reference to its argument, typically used to implement move semantics when invoking functions; that is, the function overload that takes rvalue references will be selected, and the contents of t will be moved into the function, leaving t as an xvalue.
Contents |
[edit] Parameters
| t | - | the object to be moved |
[edit] Return value
static_cast<typename std::remove_reference<T>::type&&>(t)
[edit] Exceptions
[edit] Example
#include <iostream> #include <utility> #include <vector> #include <string> int main() { std::string str = "Hello"; std::vector<std::string> v; v.push_back(str); // uses the push_back(const T&) overload std::cout << "After copy, str is \"" << str << "\"\n"; v.push_back(std::move(str)); // uses the push_back(T&&) overload std::cout << "After move, str is \"" << str << "\"\n"; std::cout << "The contents of the vector are \"" << v[0] << "\", \"" << v[1] << "\"\n"; }
Output:
After copy, str is "Hello" After move, str is "" The contents of the vector are "Hello", "Hello"
[edit] Complexity
constant
[edit] See also
| forwards a function argument (function template) | ||
| obtains an rvalue reference if the move constructor does not throw (function template) | ||
